Radio-Pathomic Maps of Cell Density Identify Brain Tumor Invasion beyond Traditional MRI-Defined Margins

BACKGROUND AND PURPOSE

Currently, contrast-enhancing margins on T1WI are used to guide treatment of gliomas, yet tumor invasion beyond the contrast-enhancing region is a known confounding factor. Therefore, this study used postmortem tissue samples aligned with clinically acquired MRIs to quantify the relationship between intensity values and cellularity as well as to develop a radio-pathomic model to predict cellularity using MR imaging data.

MATERIALS AND METHODS

This single-institution study used 93 samples collected at postmortem examination from 44 patients with brain cancer. Tissue samples were processed, stained with H&E, and digitized for nuclei segmentation and cell density calculation. Pre- and postgadolinium contrast T1WI, T2 FLAIR, and ADC images were collected from each patient's final acquisition before death. In-house software was used to align tissue samples to the FLAIR image via manually defined control points. Mixed-effects models were used to assess the relationship between single-image intensity and cellularity for each image. An ensemble learner was trained to predict cellularity using 5 × 5 voxel tiles from each image, with a two-thirds to one-third train-test split for validation.

RESULTS

Single-image analyses found subtle associations between image intensity and cellularity, with a less pronounced relationship in patients with glioblastoma. The radio-pathomic model accurately predicted cellularity in the test set (root mean squared error = 1015 cells/mm²) and identified regions of hypercellularity beyond the contrast-enhancing region.

CONCLUSIONS

A radio-pathomic model for cellularity trained with tissue samples acquired at postmortem examination is able to identify regions of hypercellular tumor beyond traditional imaging signatures.

MicroRNA 155:145 ratio as a marker of atherogenic tilt manifested across different age groups and risk factor profiles

Funding Acknowledgements

Type of funding sources: None.

Background

 Differential expression of microRNAs is critical in the genesis and progression of atherosclerosis. MiR145 has atheroprotective role through improved homeostasis of smooth muscle cells (SMC). MiR155 is pro-atherogenic due to its suppression of Bcl6, which antagonises NF-κB and modulates macrophages.

Purpose

  Our purpose was to determine if the differential expression of miR 155 & 145 (expressed as miR 155:145 ratio) across various age groups and risk factor profiles correlates with atherosclerotic cardiovascular disease (ASCVD).

Materials and Methods

  This observational cross-sectional study was done between Feb"19 & Jan"20 on 108 patients divided equally into 3 age groups: <18, 18-45 & >45yrs. Family history (of ASCVD or risk factors) and risk factor profile were assessed in all 3 groups; and in the latter two, presence or absence of ASCVD was additionally evaluated by coronary angiogram and/or carotid IMT. MiR155 & 145 were measured in all by RT-PCR, & the results were then compared after calculating the ratio.

Results

 miR 155:145 ratio was significantly increased in <18yrs aged subjects with a positive family history(p = 0.001). Multivariate regression analysis revealed a significant positive correlation of miR155:145 with family history of risk factors or ASCVD in this group(p < 0.001).

In the 18-45yrs age group, the miR 155:145 ratio was found to be significantly increased in patients with diabetes(p = 0.037) and significant coronary artery disease(CAD) as determined by Syntax score(p < 0.001). In multivariate regression analysis, a significant positive correlation was found between miR 155:145 and Syntax score(p < 0.001) – a ratio of 155:145 > 1 implied a greater chance of CAD, with increased numerical values correlating with increased severity of disease as evidenced by Syntax score; and a ratio < 1 decreased the chances of significant CAD considerably. A positive association was also discovered for this ratio with hypertension, diabetes, tobacco exposure and a combination of multiple risk factors, but none of them were statistically significant.

In the age group of >45 yrs, regression analysis revealed a statistically insignificant positive association of the miR 155:145 ratio with Syntax score, hypertension, dyslipidaemia and a combination of risk factors.

Conclusion

 MiR 155:145, when >1, can point towards an ‘atherogenic tilt’, and greater increase in the ratio numerically may denote more severe disease, as indicated by a positive association with Syntax Score. This atherogenic tilt occurs very early in life, even before 18 years with significant family history. Above 18 years, with addition of other risk factors, this tilt is further compounded, and correlated well with Syntax score and such risk factors. Therefore, miR 155:145 ratio may help in identifying the individuals at risk for development of clinically significant CAD and can be utilised for development of future therapeutic strategies as well as prognostication. Abstract Figure 1  Abstract Figure 2

Characterizing the relationships between patient reported outcomes and clinician assessments of alopecia areata in a phase 2a randomized trial of ritlecitinib and brepocitinib

Background

The phase 2a ALLEGRO trial (NCT02974868) investigated the safety and efficacy of ritlecitinib (PF‐06651600) and brepocitinib (PF‐06700841) in adults with alopecia areata. No randomized controlled trial for alopecia areata has evaluated correlations between clinician‐assessed hair loss and patient‐reported outcomes.

Objectives

Report scores from the Alopecia Areata Symptom Impact Scale (AASIS; a patient‐reported outcome tool) and explore the relationships of those scores with clinician‐assessed Severity of Alopecia Tool (SALT) scores at baseline and week 24 of the ALLEGRO trial.

Methods

Adults with alopecia areata were randomized to ritlecitinib (n = 48), brepocitinib (n = 47) or placebo (n = 47). After 24 weeks, the mixed‐effects model with repeated measures was used to calculate the active treatment groups' AASIS score least‐squares mean differences. Relationships between AASIS and SALT scores at baseline and week 24 were evaluated by Pearson's correlation coefficients using pooled data.

Results

Baseline AASIS and SALT scores were similar among treatment groups. Both active treatment groups reported significant improvements in AASIS scores at week 24 (least‐squares mean differences vs. placebo for ritlecitinib, −0.8 to −2.3; brepocitinib, −0.9 to −3.7; P < 0.05 for all). At week 24, the mean SALT scores (standard deviation) improved compared with baseline [ritlecitinib, 54.4 (40.3) vs. 89.4 (15.8); brepocitinib, 31.9 (35.7) vs. 86.4 (18.1)]. The correlation coefficients between AASIS global and subscale scores and SALT scores at week 24 ranged from 0.34 to 0.58; P < 0.05 for all.

Conclusions

Patients randomized to ritlecitinib or brepocitinib reported significantly improved AASIS and SALT scores at week 24 of the ALLEGRO trial compared to placebo. At week 24, medium‐to‐large correlations can be seen between AASIS global and subscale scores and SALT scores. Our experience with AASIS instrument highlighted several aspects that suggest new patient‐reported outcome tools are needed to accurately assess patients' relevant alopecia areata related signs, symptoms and daily functioning.

Linked Commentary: H.A. Ramírez‐Marín & A. Tosti J Eur Acad Dermatol Venereol 2022; 36: 494–495. https://doi.org/10.1111/jdv.17984.

Assessment of prescribing pattern of drugs and completeness of prescriptions as per the World Health Organization prescribing indicators in various Indian tertiary care centers: A multicentric study by Rational Use of Medicines Centers-Indian Council of Medical Research network under National Virtual Centre Clinical Pharmacology activity

OBJECTIVE

The rational use of medicines as per the World Health Organization (WHO) should be practiced globally. However, data regarding the completeness of the prescriptions and their rational use is lacking from developing countries like India. Thus, the aim of this study was to assess the prescribing patterns of drugs and completeness of prescriptions as per WHO core drug use and complementary indicators to provide real-life examples for the Indian Council of Medical Research (ICMR) online prescribing skill course for medical graduates.

METHODS

Prescriptions of the patients, fulfilling inclusion criteria, attending Outpatient Departments of various specialties of tertiary care hospitals, were collected by thirteen ICMR Rational use of medicines centers located in tertiary care hospitals, throughout India. Prescriptions were evaluated for rational use of medicines according to the WHO guidelines and for appropriateness as per standard treatment guidelines using a common protocol approved by local Ethics committees.

RESULTS

Among 4838 prescriptions, an average of about three drugs (3.34) was prescribed to the patients per prescription. Polypharmacy was noted in 83.05% of prescriptions. Generic drugs were prescribed in 47.58% of the prescriptions. Further, antimicrobials were prescribed in 17.63% of the prescriptions and only 4.98% of prescriptions were with injectables. During the prescription evaluation, 38.65% of the prescriptions were incomplete due to multiple omissions such as dose, duration, and formulation.

CONCLUSION

Most of the parameters in the present study were out of the range of WHO-recommended prescribing indicators. Therefore, effective intervention program, like training, for the promotion of rational drug use practice was recommended to improve the prescribing pattern of drugs and the quality of prescriptions all over the country.

Observational study of clinico-radiological follow-up of COVID-19 pneumonia: a district general hospital experience in the UK

BACKGROUND

The British Thoracic Society (BTS) recommends that all patients admitted with COVID-19 pneumonia should have a chest X-ray (CXR) and clinical follow-up at 6 or 12 weeks, depending on the disease severity. Little data is available on long-term CXR follow-up for moderate and severe COVID-19 pneumonia. This study aims to evaluate compliance with clinico-radiological follow-up of patients recovering from COVID-19 pneumonia at a local hospital in the UK, as per the BTS guidance, and to analyse radiological changes at clinical follow-up at 12 weeks, in order to risk-stratify and improve patient outcomes.

METHODS

This is a single-centre retrospective audit of 255 consecutive COVID-19 positive patients admitted to a local hospital in the UK over 5 months between May and October 2020. All CXRs and clinic follow-up at 12 ± 8 weeks were checked on an electronic database.

RESULTS

Over one in two (131/255) patients had CXR evidence of COVID-19 pneumonia during the initial hospital admission. Half of the patients (60/131) died before CXR or clinic follow-up. Fifty-eight percent (41/71) of the surviving patients had a follow-up CXR, and only two developed respiratory complications- one had residual lung fibrosis, another a pulmonary embolism. Eighty-eight percent (36/41) of the patients had either resolution or improved radiological changes at follow-up. Most patients who had abnormal follow-up CXR were symptomatic (6/8), and many asymptomatic patients at follow-up had a normal CXR (10/12).

CONCLUSIONS

Although there were concerns about interstitial lung disease (ILD) incidence in patients with COVID-19 pneumonia, most of our patients with COVID-19 pneumonia had no pulmonary complications at follow-up with CXR. This emphasises that CXR, a cost-effective investigation, can be used to risk-stratify patients for long term pulmonary complications following their COVID-19 pneumonia. However, we acknowledge the limitations of a low CXR and clinic follow-up rate in our cohort.

Correlation of Four Single Nucleotide Polymorphisms of the RELN Gene With Schizophrenia

OBJECTIVE

This study aims to determine the association between single-nucleotide polymorphisms (SNPs) of the RELN gene and schizophrenia.

METHODS

134 patients aged 16 to 58 (mean, 38.0) years who were diagnosed with acute or chronic schizophrenia at the Zhongshan Third People's Hospital between January 2018 and April 2020 were recruited, as were 64 healthy controls aged 22 to 59 (mean, 45.6) years who matched with the age and sex of the patients. MassARRAY mass spectrometry genotyping technology was used to determine the genotypes of four SNPs of RELN (rs2073559, rs2229864, rs362691, and rs736707).

RESULTS

There were no significant between-group or between-sex differences in terms of genotype, allele frequency, or haplotype frequency of the SNPs (all p > 0.05). In the association analysis between genotypes and quantitative traits in the Positive and Negative Syndrome Scale, rs2229864 and rs736707 were associated with the scores for items P3 (hallucinatory behaviour) and G11 (attention disorder), and rs362691 was associated with G10 (disorientation). However, the associations did not remain significant after Bonferroni correction.

CONCLUSION

Multiple pathogenic polymorphisms of RELN might be associated with hallucinatory behaviour and attention disorder in Chinese patients with schizophrenia.

Brain mapping across 16 autism mouse models reveals a spectrum of functional connectivity subtypes

Autism Spectrum Disorder (ASD) is characterized by substantial, yet highly heterogeneous abnormalities in functional brain connectivity. However, the origin and significance of this phenomenon remain unclear. To unravel ASD connectopathy and relate it to underlying etiological heterogeneity, we carried out a bi-center cross-etiological investigation of fMRI-based connectivity in the mouse, in which specific ASD-relevant mutations can be isolated and modeled minimizing environmental contributions. By performing brain-wide connectivity mapping across 16 mouse mutants, we show that different ASD-associated etiologies cause a broad spectrum of connectional abnormalities in which diverse, often diverging, connectivity signatures are recognizable. Despite this heterogeneity, the identified connectivity alterations could be classified into four subtypes characterized by discrete signatures of network dysfunction. Our findings show that etiological variability is a key determinant of connectivity heterogeneity in ASD, hence reconciling conflicting findings in clinical populations. The identification of etiologically-relevant connectivity subtypes could improve diagnostic label accuracy in the non-syndromic ASD population and paves the way for personalized treatment approaches.

Finite size effect on the magnetic glass

The nature of glass formation and crystallization in structural glass is yet to be understood despite the intense studies of many decades. Analogous to the structural glasses, hindered first order magnetic transitions produce magnetic glasses, where the volume fraction of two phases having long range structural and magnetic order are frozen in time. Here, we have prepared Pr_0.5Ca_0.5Mn_0.975Al_0.025O₃nanoparticles of different size as a case study and investigated the formation and stability of the magnetic glass state at the length scale of a few nanometers. We have observed a profound interplay between the glass state and sample size: stability of the glass state highly increases and scales linearly with decrease in the sample size. Smaller the particle size, slower is the crystallization rate. The crystallization occurs through both homogeneous and heterogeneous nucleation and is controlled by the surface to volume ratio of the particles. Our results emphasize on an important fact that glass transition is not a phase transition in actual sense, rather it is a kinetic phenomena. The length scale associated with different nucleation processes is an important length scale and it controls the glass dynamics. Besides, apart from the intrinsic metastability due to magnetic glass, we also distinguish a secondary source of relaxation, which is dominant at low magnetic fields, predominantly arising due to surface spin disorder.

Lower gastrointestinal bleeding in pregnancy: Differential diagnosis, assessment and management

Rectal bleeding is a common symptom experienced by pregnant women. Although the majority of cases are attributable to benign conditions such as haemorrhoids and anal fissures, other more serious diagnoses such as inflammatory bowel disease and malignancy should not be overlooked. Most investigations are safe during pregnancy and these should not be withheld as significant implications on both fetal and maternal morbidity may result. In these cases, a multidisciplinary team approach is essential. This review explores the differential diagnosis, investigation and management of rectal bleeding during pregnancy.

Active microrheology using pulsed optical tweezers to probe viscoelasticity of lamin A

Lamins are nucleoskeletal proteins of mammalian cells that stabilize the structure and maintain the rigidity of the nucleus. These type V intermediate filament proteins which are predominantly of A and B types provide necessary tensile strength to the nucleus. Single amino acid missense mutations occurring all over the lamin A protein form a cluster of human diseases termed as laminopathies, most of which principally affect the muscle and cardiac tissues responsible for load bearing functionalities of the body. One such mutation is A350P which causes dilated cardiomyopathy in patients. It is postulated that a change from alanine to proline in the α-helical coiled-coil forming 2B rod domain of the protein might severely disrupt the propensity of the filaments to polymerise into functional higher order structures required to form a fully functional lamina with its characteristic elasticity. In this study, we have elucidated for the very first time, the application of active microrheology employing oscillating optical tweezers to investigate any alterations in the viscoelastic parameters of the mutant protein meshwork in vitro, which might translate into possible changes in nuclear plasticity. We confirmed our findings from this robust yet fast method by imaging both the wild type and mutant lamin A networks using a super resolution microscope, and observed changes in the mesh size which corroborate our measured changes in the viscoelastic parameters of the lamins. This method could thus be extended to conduct microrheological measurements on any intermediate filament protein thus bearing significant implications in laminopathies and other diseases associated with intermediate filaments.

Do Multiple Drug Resistance Transporters Interfere with Cell Functioning under Normal Conditions?

Eukaryotic cells rely on multiple mechanisms to protect themselves from exogenous toxic compounds. For instance, cells can limit penetration of toxic molecules through the plasma membrane or sequester them within the specialized compartments. Plasma membrane transporters with broad substrate specificity confer multiple drug resistance (MDR) to cells. These transporters efflux toxic compounds at the cost of ATP hydrolysis (ABC-transporters) or proton influx (MFS-transporters). In our review, we discuss the possible costs of having an active drug-efflux system using yeast cells as an example. The pleiotropic drug resistance (PDR) subfamily ABC-transporters are known to constitutively hydrolyze ATP even without any substrate stimulation or transport across the membrane. Besides, some MDR-transporters have flippase activity allowing transport of lipids from inner to outer lipid layer of the plasma membrane. Thus, excessive activity of MDR-transporters can adversely affect plasma membrane properties. Moreover, broad substrate specificity of ABC-transporters also suggests the possibility of unintentional efflux of some natural metabolic intermediates from the cells. Furthermore, in some microorganisms, transport of quorum-sensing factors is mediated by MDR transporters; thus, overexpression of the transporters can also disturb cell-to-cell communications. As a result, under normal conditions, cells keep MDR-transporter genes repressed and activate them only upon exposure to stresses. We speculate that exploiting limitations of the drug-efflux system is a promising strategy to counteract MDR in pathogenic fungi.

Melatonin application differentially modulates the enzymes associated with antioxidative machinery and ascorbate-glutathione cycle during arsenate exposure in indica rice varieties

Arsenic (As) contamination and accumulation in rice is a serious concern causing severe oxidative damage. Melatonin acts as a protective agent in plant defence against multiple abiotic stresses. The mechanism of antioxidant function of melatonin during As stress in rice genotypes is less studied. In this study, hydroponically-grown As-susceptible (Khitish) and As-tolerant (Muktashri) rice cultivars, subjected to 150 µm arsenate stress, were supplemented with exogenously applied melatonin (20 µm) to examine the plant defence mechanism. Melatonin (Mel) increased root and shoot length, fresh and dry weight, chlorophyll a and b content and activated reducing power and free radical scavenging capacity in both rice cultivars. The role of Mel in the sensitive variety appeared to be more prominent with respect to reduced water saturation deficit by reducing endogenous As and H₂ O₂ accumulation, and enhancing overall antioxidant capacity by imposing reduced requirement of catalase for ROS detoxification, and restoring As-inhibited activity of glutathione-S-transferase, glutathione peroxidase and dehydroascorbate reductase. In contrast, melatonin treatment in the tolerant cultivar required reduced involvement of ascorbate peroxidase to deal with As toxicity, and complemented the stress-mediated inhibition of guaiacol peroxidase activity. Isozyme profiling also established extensive varietal differences with regard to induction of new isoform(s) by Mel during As treatment. This study provides clear insights into mechanistic details of the regulation of antioxidative enzymes by melatonin in contrasting rice genotypes, which may prove helpful in generating As tolerance in susceptible rice varieties grown in marginalized soils, thereby improving crop yield and productivity.

A large outbreak of measles in the West Midlands, England, 2017-2018: descriptive epidemiology, control measures and lessons learnt

In November 2017, eight confirmed measles cases were reported to Public Health England from a hospital in the West Midlands. A multidisciplinary Incident Management Team (IMT) was established to determine the extent of the problem and coordinate an outbreak response. Between 1 November 2017 and 4 June 2018, a total of 116 confirmed and 21 likely measles cases were linked to this outbreak; just under half (43%) were aged over 15 years of age. Fifty-five of the confirmed cases were hospitalised (48%) and no deaths were reported. At the start of the outbreak, cases were mostly individuals of Romanian origin; the outbreak subsequently spread to the wider population. Over the 8-month response, the IMT conducted the following control measures: extensive contact tracing, immediate provision of post-exposure prophylaxis, community engagement amongst specific high-risk groups, MMR awareness raising including catch-up campaigns and enhanced vaccination services at selected GP surgeries. Key challenges to the effective control measures included language difficulties limiting community engagement; delays in diagnosis, notification and appropriate isolation of cases; limited resources for contact tracing across multiple high-risk settings (including GPs and hospitals) and lack of timely data on vaccine coverage in sub-groups of the population to guide public health action.

Obesity during the COVID-19 pandemic: both cause of high risk and potential effect of lockdown? A population-based electronic health record study

OBJECTIVES

Obesity is a modifiable risk factor for coronavirus disease 2019 (COVID-19)-related mortality. We estimated excess mortality in obesity, both 'direct', through infection, and 'indirect', through changes in health care, and also due to potential increasing obesity during lockdown.

STUDY DESIGN

The study design of this study is a retrospective cohort study and causal inference methods.

METHODS

In population-based electronic health records for 1,958,638 individuals in England, we estimated 1-year mortality risk ('direct' and 'indirect' effects) for obese individuals, incorporating (i) pre-COVID-19 risk by age, sex and comorbidities, (ii) population infection rate and (iii) relative impact on mortality (relative risk [RR]: 1.2, 1.5, 2.0 and 3.0). Using causal inference models, we estimated impact of change in body mass index (BMI) and physical activity during 3-month lockdown on 1-year incidence for high-risk conditions (cardiovascular diseases, diabetes, chronic obstructive pulmonary disease and chronic kidney disease), accounting for confounders.

RESULTS

For severely obese individuals (3.5% at baseline), at 10% population infection rate, we estimated direct impact of 240 and 479 excess deaths in England at RR 1.5 and 2.0, respectively, and indirect effect of 383-767 excess deaths, assuming 40% and 80% will be affected at RR = 1.2. Owing to BMI change during the lockdown, we estimated that 97,755 (5.4%: normal weight to overweight, 5.0%: overweight to obese and 1.3%: obese to severely obese) to 434,104 individuals (15%: normal weight to overweight, 15%: overweight to obese and 6%: obese to severely obese) would be at higher risk for COVID-19 over one year.

CONCLUSIONS

Prevention of obesity and promotion of physical activity are at least as important as physical isolation of severely obese individuals during the pandemic.

Non-equilibrium magnetic response of canonical spin glass and magnetic glass

Time and history dependent magnetization has been observed in a wide variety of materials, which are collectively termed as the glassy magnetic systems. However, such systems showing similar non-equilibrium magnetic response can be microscopically very different and they can be distinguished by carefully looking into the details of the observed metastable magnetic behavior. Canonical spin glass (SG) is the most well studied member of this class and has been extensively investigated both experimentally and theoretically over the last five decades. In canonical SGs, the low temperature magnetic state obtained by cooling across the SG transition temperature in presence of an applied magnetic field is known as the field cooled (FC) state. This FC state in canonical SG is widely believed as an equilibrium state arising out of a thermodynamic second order phase transition. Here, we show that the FC state in canonical SG is not really an equilibrium state of the system. We report careful dc magnetization and ac susceptibility measurements on two canonical SG systems, AuMn (1.8%) and AgMn (1.1%). The dc magnetization in the FC state shows clear temperature dependence. In addition, the magnetization shows a distinct thermal hysteresis in the temperature regime below the SG transition temperature. On the other hand, the temperature dependence of ac susceptibility has clear frequency dispersion below SG transition in the FC state prepared by cooling the sample in the presence of a dc-bias field. We further distinguish the metastable response of the FC state of canonical SG from the metastable response of the FC state in an entirely different class of glassy magnetic system namely magnetic glass, where the non-equilibrium behavior is associated with the kinetic-arrest of a first order magnetic phase transition.

Quantitative material analysis using secondary electron energy spectromicroscopy

This paper demonstrates how secondary electron energy spectroscopy (SEES) performed inside a scanning electron microscope (SEM) can be used to map sample atomic number and acquire bulk valence band density of states (DOS) information at low primary beam voltages. The technique uses an electron energy analyser attachment to detect small changes in the shape of the scattered secondary electron (SE) spectrum and extract out fine structure features from it. Close agreement between experimental and theoretical bulk valance band DOS distributions was obtained for six different test samples, where the normalised root mean square deviation ranged from 2.7 to 6.7%. High accuracy levels of this kind do not appear to have been reported before. The results presented in this paper point towards SEES becoming a quantitative material analysis companion tool for low voltage scanning electron microscopy (LVSEM) and providing new applications for Scanning Auger Microscopy (SAM) instruments.